Estrogens include a group steroid hormones essential for normal development and for the healthy functioning of the reproductive system. Three of these estrogens include 17.beta. estradiol, estriol, and estrone. Evaluation of "free" estrogen levels can have diagnostic importance in screening for abnormal patterns of changes in estrogen solubility levels such as is observed in the growths of certain estrogen dependent tumors, occurrence of cystic ovaries, and the development of possible endometriosis in the reproductive organs of females. In some female mammals changes in concentration of "free" estrogens are known to occur at the time of implantation and before the onset of parturition. It is also known that "free" estrogen levels vary at different times of the life span of a mammal. During fetal development the concentration of estrogens are known to increase in the third trimester of pregnancy due to increased levels of one estrogen form called estriol which is produced by the adrenal glands of the fetus. Prior to delivery, estrogen levels increase significantly in serum and saliva of different species of pregnant mammals. After delivery, estrogen levels fall rapidly in the mother and babies have low levels of "free" estrogens.
It is also known that estrogen levels increase significantly in girls before they reach puberty. As women age, their ability to produce estrogen decreases after the onset of menopause and "free" estrogen levels reach very low levels between 70 and 80 years. Estrogen levels also fall when ovaries are removed from all animal species.
Certain activities such as excessive sports can also diminish "free" estrogen levels. Some cases of anovulation have chronic higher levels of estrogen but fail to reach peak levels of estrogen concentration and can result in a condition known as cystic ovaries. Also some people do not have the ability to control levels of estrogen and have an abnormal situation like excessive bone growth.
Only a small percentage (1% in human females) of the total estrogens in the body are not chemically bound. These estrogens are called "free" estrogens and are considered to have hormone effects on certain body functions such as those described in the previous paragraphs.
The following chart demonstrates examples of how "free" estrogen levels vary for different species and conditions.
______________________________________ Amount of total The amount of free Species estrogen in serum estrogen in saliva ______________________________________ Woman who has 10-30 1-3 picograms/ml passed through picograms/ml menopause Boys age 7 .02 pg/ml Girl before puberty .6 pg/ml 1-2 picograms/ml usually between ages 5 and 8 A woman who is in 25-75 1-4 picograms/ml follicule phase picograms/ml of menstrual cycle and has ovaries A girl at puberty or 200-900 2-9 picograms/ml approaching puberty picograms/ml A woman that will 200-900 4.5 picograms/ml ovulate within picograms/ml to 9 picograms/ml four days A pregnant woman 1000 to 5000 40-100 picograms/ml in the first 3 picograms/ml months of pregnancy A pregnant woman 6000 to 16000 50-100 picograms/ml in 2nd trimester of picograms/ml/ml pregnancy A pregnant woman 10000 to 40000 50-150 picograms/ml in the last picograms/ml trimester of pregnancy Cow in early 3.5 +/- 0.7 pg/ml Not measured leutal phase Cow two days 5.1 -/- 0.3 pg/ml Not measured before estrus Cow at estrus 7.1 +/- 0.6 pg/ml Not measured ______________________________________
The body has a system to regulate the total amount of "free" estrogens at any given time. An ovulating woman can absorb at least 9 picograms of free estrogen in her saliva. A woman who is about to deliver a baby will be able to absorb at least 200 picograms of "free" estrogen in her saliva. An old woman who is menopausal will have only 1-2 picograms of "free" estrogen in her saliva. In each situation the body is able to recognize when the capacity to have "free" estrogens is reached. Excess estrogens become bound to other components in the body fluids thus preventing these excess estrogens from acting as hormones.
Accordingly, a system that can evaluate whether or not the body has reached its capacity to hold "free" estrogens can have many useful applications and can have considerable clinical value and importance as a tool for screening for various conditions affected by changes in "free" estrogen levels. This is especially true in females. It can be used to evaluate when a body fluid is increasing its capacity to hold "free" estrogens such as is observed in serum and saliva prior to parturition. It can also be used by menopausal women to monitor how the body is absorbing estrogen therapy. It can further evaluate imbalances in "free" estrogen levels such as observed in ovarian cysts. It can track estrogen level changes in the normal development of an individual such as in the last stages of fetal development, the onset of puberty, menopause, and other estrogen dependent events.
Current methods to evaluate estrogen levels often need to separate total estrogens into fractions of bound and unbound estrogens. This process involves a series of complicated analytical procedures that are time consuming and frequently require several hours. Furthermore the instrumentation to accomplish this process needs special facilities that are usually only available in research laboratories, clinics, or hospitals. Additionally, many estrogen assays have limited accuracy and frequently must be repeated many times.
The use of anthocyanins pigments as a fertility evaluation medium is known and is described in U.S. Pat. No. 4,358,288 to Goldman. This patent describes evaluating fertility in females by contacting a mucin-containing body fluid such as saliva with a fertility evaluation medium comprising an anthocyanin pigment and a substrate which facilitates generation of a color response in this pigment in the presence of a vaginal fluid or substance similar to those found in vaginal fluids. This patent does not, however, suggest that observed color changes in anthocyanin pigments under certain specific conditions can be correlated with the capacity of body fluids to hold free, unbound estrogens and can be used to screen for estrogen dependent physiological changes in the body that do not include fertility evaluation.
It is accordingly an object of the present invention to provide a method to easily and rapidly determine whether or not a given body fluid such as saliva, serum, or interstitial fluid has reached its maximum capacity to hold the "unbound" estrogen in order to assess for changes in certain physiological conditions that are estrogen dependent.
It is another object of the present invention to provide a simple, easy to use, quick marker system for "free" estrogen solubility and methodology which permits identification of changes in the body's capacity to hold "free" estrogens based upon optical properties such as color change.
Yet another object of the invention is to provide a simple yet effective method to quantitatively determine what is the additional capacity for "free" estrogens in a body fluid such as saliva, serum, or interstitial fluids.